board/hammer: Add variant with backlight totally disabled

Some boards lack the external pull-up to indicate absence of
keyboard backlight, so add a new HAS_BACKLIGHT define.

Also, remove support for long deprecated early staff boards,
and move backlight detection to RW only.

BRANCH=none
BUG=b:67722756
BUG=b:140596094
TEST=make BOARD=masterball -j

Change-Id: I20d83ec9df64e2b00eed2ca540e4d302bbbee4d1
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1833034
Reviewed-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Yilun Lin <yllin@chromium.org>

4 files changed, 34 insertions, 25 deletions

diff --git a/board/hammer/board.c b/board/hammer/board.c
index aec8f457f4..c8ebbd856e 100644
--- a/board/hammer/board.c
+++ b/board/hammer/board.c
@@ -98,17 +98,13 @@ const struct i2c_port_t i2c_ports[] = {
 const unsigned int i2c_ports_used = ARRAY_SIZE(i2c_ports);
 #endif
 
-#ifdef BOARD_STAFF
-#define KBLIGHT_PWM_FREQ 100 /* Hz */
-#else
-#define KBLIGHT_PWM_FREQ 50000 /* Hz */
-#endif
-
+#ifdef HAS_BACKLIGHT
 /* PWM channels. Must be in the exactly same order as in enum pwm_channel. */
 const struct pwm_t pwm_channels[] = {
 	{STM32_TIM(TIM_KBLIGHT), STM32_TIM_CH(1), 0, KBLIGHT_PWM_FREQ},
 };
 BUILD_ASSERT(ARRAY_SIZE(pwm_channels) == PWM_CH_COUNT);
+#endif /* HAS_BACKLIGHT */
 
 int usb_i2c_board_is_enabled(void)
 {
@@ -163,29 +159,16 @@ static struct usart_config const ec_ec_usart =
  */
 static int has_keyboard_backlight;
 
+#ifdef SECTION_IS_RW
 static void board_init(void)
 {
+#ifdef HAS_BACKLIGHT
 	/* Detect keyboard backlight: pull-down means it is present. */
 	has_keyboard_backlight = !gpio_get_level(GPIO_KEYBOARD_BACKLIGHT);
 
 	CPRINTS("Backlight%s present", has_keyboard_backlight ? "" : " not");
+#endif /* HAS_BACKLIGHT */
 
-#ifdef BOARD_STAFF
-	if (!has_keyboard_backlight) {
-		/*
-		 * Earlier staff boards have both PU and PD stuffed, and end up
-		 * being detected as not have keyboard backlight. However, we
-		 * need to enable internal PD on the pin, otherwise backlight
-		 * will always be on.
-		 * TODO(b:67722756): Remove this hack when old boards are
-		 * deprecated.
-		 */
-		gpio_set_flags(GPIO_KEYBOARD_BACKLIGHT,
-			       GPIO_PULL_DOWN | GPIO_INPUT);
-	}
-#endif /* BOARD_STAFF */
-
-#ifdef SECTION_IS_RW
 #ifdef BOARD_WAND
 	/* USB to serial queues */
 	queue_init(&ec_ec_comm_slave_input);
@@ -221,10 +204,10 @@ static void board_init(void)
 	gpio_config_module(MODULE_SPI_MASTER, 1);
 	spi_enable(CONFIG_SPI_TOUCHPAD_PORT, 1);
 #endif /* HAS_SPI_TOUCHPAD */
-#endif /* SECTION_IS_RW */
 }
 /* This needs to happen before PWM is initialized. */
 DECLARE_HOOK(HOOK_INIT, board_init, HOOK_PRIO_INIT_PWM - 1);
+#endif /* SECTION_IS_RW */
 
 void board_config_pre_init(void)
 {
diff --git a/board/hammer/board.h b/board/hammer/board.h
index 82becc803b..5eca65a6f9 100644
--- a/board/hammer/board.h
+++ b/board/hammer/board.h
@@ -188,7 +188,9 @@
 #ifdef SECTION_IS_RW
 #define CONFIG_USB_HID
 #define CONFIG_USB_HID_KEYBOARD
+#ifdef HAS_BACKLIGHT
 #define CONFIG_USB_HID_KEYBOARD_BACKLIGHT
+#endif
 
 #ifndef HAS_NO_TOUCHPAD
 #define CONFIG_USB_HID_TOUCHPAD
@@ -215,7 +217,9 @@
 #endif
 
 /* Enable PWM */
+#ifdef HAS_BACKLIGHT
 #define CONFIG_PWM
+#endif
 
 #ifdef CONFIG_GMR_TABLET_MODE
 #define CONFIG_TABLET_MODE
@@ -336,17 +340,19 @@ enum usb_strings {
 };
 
 #ifdef SECTION_IS_RW
+#ifdef HAS_BACKLIGHT
 enum pwm_channel {
 	PWM_CH_KBLIGHT = 0,
 	/* Number of PWM channels */
 	PWM_CH_COUNT
 };
+#endif /* HAS_BACKLIGHT */
 
 enum adc_channel {
 	/* Number of ADC channels */
 	ADC_CH_COUNT
 };
-#endif
+#endif /* SECTION_IS_RW */
 
 #endif /* !__ASSEMBLER__ */
 #endif /* __CROS_EC_BOARD_H */
diff --git a/board/hammer/gpio.inc b/board/hammer/gpio.inc
index a687c44390..a94c0aa7e4 100644
--- a/board/hammer/gpio.inc
+++ b/board/hammer/gpio.inc
@@ -93,7 +93,9 @@ GPIO(EN_PP3300_TP_ODL,		PIN(A, 14), GPIO_OUT_LOW)
 #endif
 #endif /* !HAS_NO_TOUCHPAD */
 
+#ifdef HAS_BACKLIGHT
 GPIO(KEYBOARD_BACKLIGHT,	PIN(B, 9), GPIO_INPUT)
+#endif
 
 GPIO(WP_L,			PIN(A, 13), GPIO_INPUT | GPIO_PULL_UP)
 
@@ -131,4 +133,6 @@ ALTERNATE(PIN_MASK(B, 0x0038), 0, MODULE_SPI_MASTER, 0) /* SPI MASTER:PB3/4/5 */
 ALTERNATE(PIN_MASK(B, 0x00c0), 1, MODULE_I2C, 0) /* I2C TOUCHPAD: PB6/7 GPIO_ODR_HIGH */
 #endif
 
+#ifdef HAS_BACKLIGHT
 ALTERNATE(PIN_MASK(B, 0x0200), 2, MODULE_PWM, GPIO_PULL_DOWN) /* PWM: PB9 */
+#endif
diff --git a/board/hammer/variants.h b/board/hammer/variants.h
index c50d0307cb..ac50e5265b 100644
--- a/board/hammer/variants.h
+++ b/board/hammer/variants.h
@@ -80,11 +80,27 @@
 #define CONFIG_KEYBOARD_ASSISTANT_KEY
 #endif
 
-/* Backlight driver */
+/* Backlight */
+#if defined(BOARD_HAMMER) || defined(BOARD_STAFF) || \
+    defined(BOARD_WAND) || defined(BOARD_WHISKERS)
+/*
+ * Even with this option, we detect the backlight presence using a PU/PD on the
+ * PWM pin. Not defining this totally disables support.
+ */
+#define HAS_BACKLIGHT
+
 #ifdef BOARD_WHISKERS
 #define CONFIG_LED_DRIVER_LM3630A
 #endif
 
+#ifdef BOARD_STAFF
+#define KBLIGHT_PWM_FREQ 100 /* Hz */
+#else
+#define KBLIGHT_PWM_FREQ 50000 /* Hz */
+#endif
+
+#endif /* BOARD_HAMMER/WAND/WHISKERS */
+
 /* GMR sensor for tablet mode detection */
 #if defined(BOARD_MASTERBALL) || defined(BOARD_WHISKERS)
 #define CONFIG_GMR_TABLET_MODE